1. Field of the Invention
This invention is related to an apparatus and a method for testing thermal fatigue resistance, and belongs to the engineering field of testing thermal fatigue resistance.
2. Description of the Related Art
A technique for testing thermal fatigue resistance is disclosed in Japanese Unexamined Patent Publication (KOKAI) No.7-020031. It is a testing technique in which a test piece is put between two pieces of a holder with thermal expansion coefficient different from the coefficient of the test piece, and the test unit consisting of the test piece and the holder is heated up and cooled down. The difference in the thermal expansion coefficient between the test piece and the holder is used to cause the required strain on the test piece, so that thermal fatigue test is performed.
In the testing technique described above, any actuators are not necessary to cause the mechanical strain in the test piece, so the technique has some advantage in the cost of the testing facility. The technique, however, was still to be improved because the facility was not compact enough nor simple enough, as it needed both means for heating and means for cooling separately. Also, heating and cooling of the whole test unit caused nonuniform temperature distribution due to difference of thermal capacity in every part of the test unit and made it difficult to give a required temperature distribution intentionally to the test piece.
Thus, the purpose of the invention is to provide an apparatus for testing thermal fatigue resistance which has unified means for heating and cooling and can provide a smaller and simpler set up, and to provide a method for testing thermal fatigue resistance by which required temperature distribution on the test unit can be obtained intentionally.